SOLUTION: A bus took a 700 mile trip in 12 hours. The speed was 75 mph for the first part of the trip, and 50 mph for the return trip. How many hours were traveled at each speed?

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Question 640045: A bus took a 700 mile trip in 12 hours. The speed was 75 mph for the first part of the trip, and 50 mph for the return trip. How many hours were traveled at each speed?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A bus took a 700 mile trip in 12 hours.
The speed was 75 mph for the first part of the trip, and 50 mph for the return trip.
How many hours were traveled at each speed?
:
Let t = time in hrs at 75 mph
The total travel time is given as 12 hrs, therefore
(12-t) = time at 55 mph
:
Write a distance equation; dist = speed * time
75t + 50(12-t) = 700
75t + 600 - 50t = 700
75t - 50t = 700 - 600
25t = 100
t = 100/25
t = 4 hrs at 75 mph
then
12-4 = 8 hrs at 50 mph
:
:
Check this by finding the distance at each speed
4(75) = 300 mi
8(50) = 400 mi
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total: 700 mi